Apparatus for tensioning strands



7, 1950 TAYLOR 2,499,888

APPARATUS FOR TENSIONING STRANDS Filed 001;. 50, 1945 3 Sheets-Sheet 1March 7, 1950 F. TAYLOR 2,499,888

APPARATUS FOR TENSIONING STRANDS Filed Oct. 30, 1945 3 Sheets-Sheet 2March 1950 F. TAYLOR 2,499,888

APPARATUS FOR TENSIONING STRANDS FiledOcL- 50, 1945 3 Sheets-Sheet 3Patented Mar. 7, 1950 UNITED STATES PATENT OFFICE APPARATUS FORTENSIONING STRANDS Application 0ctober 30, 1945, Serial No. 625,593

2 Claims.

This invention pertains to textile manufacture, and relates moreparticularly to a novel means for and method of tensioning elasticelements, for instanc rubber-elastic threads or strands. While theinvention is of especial importance for the tensioning of rubber-elasticthreads preparatory to incorporating them in a fabric, it is alsoapplicable to the tensioning of strands which are not elastic likerubber, as well as for tensioning sheet material. When hereinafterreference is made to strands without other limitation, this term isunderstood to be inclusive of any elongate flexible element regardlessof its width, that is to say, whether it is in the nature of a filamentor a sheet, and regardless of whether or not it is elastic like rubber.Further, when rubber-elastic is referred to, this term is intended todenote the stretch characteristics of the material as rubber-like andnot necessarily that the material is or contains rubber.

Among specific uses of this improved tension, and to which referencewill hereinafter be made, are the delivery of rubber-elastic warps orsingle rubber strands for incorporation in a woven fabric; to thedelivery of rubber-elastic threads for incorporation either as coreelements or as a part of the braided structure itself, in themanufacture of braided fabrics; to the delivery of elastic threads torubber covering machines; or in fact to the delivery of rubber elasticstrands to machines or other equipment to which such strands should befed under a constant predetermined tension.

Many difficulties are inherent in the handling of rubber-elastic strandsin weaving, braiding, knitting or the like, which are not encounteredwhen using ordinary textile strands, and complicated and troublesomepreparatory steps and/or the use of complex tensioning devices haveheretofore been necessary for the manipulation of such rubber-elasticstrands during fabric manufacture. When rubber-elastic strands are drawnoff from a wound mass of the strand material, for instance a warp beam,the gradual decrease in diameter of the wound mass as the operationprogresses, requires a corresponding adjustment of the tension mechanismin order to insure uniform unwinding tension. Rubberelastic threadselongate much more than ordinary textile yarns in response to tension,and most prior tensioning devices are to some extent at least responsiveto such factors as variation in atmospheric moisture or temperature.Thus it has been very diflicult to make an elastic fabric which isuniform in texture, appearance and resistance to elongation. Since therubber-elastic threads are so different in characteristics from thetextile yarns with which they are usue ally combined, it has heretoforebeen thought necessary to wind the rubber-elastic strands upon a specialwarp beam preparatory to weaving, but even this procedure of itself isdifiicult and demands great care and skill in so winding therubber-elastic threads upon the warp beam as to insure uniform unwindingtension. Moreover, this special warp beam with its accessories occupiessubstantial space in the loom structure. Likewise, in braiding, therubber-elastic threads are often wound upon separate spools, and greatdifficulty is experienced in letting off each of the severalrubber-elastic threads so that they all approach the braiding mechanismunder equal tension, the result being that the edges of flat elasticbraid are usually uneven and the braid itself is wavy and lacks thedesired uniformity and finish.

The basic conception upon which the present invention is predicated isthe discovery that the elastic recovery force of a stretched elasticelement may be employed in maintaining uniformity of tension of saidelement. This concept embodied in a simple mechanical construction ashereinafter more fully described, makes it possible to apply asubstantially constant predetermined tension to substantially any numberof elastic strands or threads without recourse to the complicatedtension means customarily employed in th effort (heretoforeunsuccessful) to attaining this desirable result.

One object of the present invention is to provide a novel method of andmeans for delivering rubber-elastic strands of as great individuallength and in as great a number as may be desired, at substantiallyconstant and uniform tension, to the point of use. A further object isto provide a novel method of tensioning rubberelastic warps whereby theuse of a warp beam for the rubber strands is dispensed with. A furtherobject is to provide tensioning means applicable to weaving, braiding,rubber covering, knitting or the like, and capable of handlingsubstantially as many rubber threads as may be desired but in a verysmall space. A further object is to provide tensioning means capable ofuse with so-called ribbon rubber, that is to say, rubber threadsdisposed in the same plane and cohering at their adjacent edges so as toform a ribbon-like strand which is easily separated into its constituentthreads. A further object is to provide tensioning means of simple,reliable, durable and inexpensive type applicable to looms, braiders,rubber covering machines and the like, without substantial modification(except as respects size) and which is operative to deliver each of alarge number of threads with the same and uniform tension. Other andfurther objects and advantages of the invention will be pointed out inthe following more detailed description and by reference to theaccompanying drawings,

60 wherein Fig. 1 is a fragmentary diagrammatic side view, partly invertical section, showing portions of the frame and certain otherelements of a weaving loom designed to interweave rubber elastic threadswith textile yarns, and showing details of the tensioning means of thepresent invention;

Fig. 2 is a fragmentary vertical section showing the tension means ofFig. 1, but viewed from the opposite side of the loom;

Fig. 3 is a plan view, to larger scale, of the tensioning means of Fig.1;

Fig. 4 is a perspective view, to larger scale than Fig. 1, and withparts broken away, illustrating a desirable dividing means forseparating alternate threads of ribbon rubber;

Fig. 5 is a fragmentary perspective view showing a desirable form ofcomb for guiding the separated rubber threads;

Fig. 6 is a diagrammatic side elevation showing the improved tensionapplied to a braiding machine of conventional type in which rubberthreads are incorporated as a core in a tubular braid;

Fig. '7 is a fragmentary rear elevation, to larger scale, of thetensioning means of Fig. 6;

Fig. 8 is a diagrammatic end view showing how several strands of ribbonrubber may simultaneously be fed through the tensioning means of thepresent invention;

Fig. 9 is a diagrammatic side elevation showing the tensioning means ofthe present invention applied to a conventional braiding machine inwhich rubber elastic threads are incorporated in the braided fabric; and

Fig. 10 is a plan view illustrating the construction of ribbon rubber.

Referring to the drawings and in particular to Figs. 1 to 5 inclusive,the numeral I designates a horizontal rail which may form a part of therear structure of a conventional weaving loom, for instance a narrowware loom employed in weaving elastic webbing. As illustrated, the loomcomprises a horizontal comb or reed 2 for guiding textile yarns 3 from asuitable source of supply, for example a warp beam (not shown), to ahorizontal guide roller 4 from which these yarns pass to the heddles bymeans of which they are formed into a shed, as indicated at 55. Thenumeral 8 indicates the path of rubber-elastic threads which aredelivered substantially in the horizontal plane of the forming cloth webby passing over an elongate anti-friction roller 1, carried by ahorizontal fixed shaft 6.

The improved tensioning means T of the present invention is hereinillustrated as comprising a supporting bracket 9 mounted upon the upperedge of the rail I and having spaced aligned bearings for a horizontalshaft I on which is mounted the tensioning roll II. This roll is ofsubstantial diameter, for example five inches, and is of rigid material.If desired, this roll may have a friction surface, for instance a tightand firm covering of textile fabric, rubber or the like, but preferablyit is of metal and smooth and polished. The roll I I is fixed to theshaft I0 and a brake drum or pulley I2 (Fig. 2) is also fixed to theshaft I9 and is embraced by a brake band I3. Preferably this brake bandis in the form of a cord and it may make one or more turns about thebrake drum or pulley I2, as desired. One end of this brake band I3 isfixed to a suitable anchorage, ere shown as a screw eye I4 set into therail I, while its other end is connected to a tension spring I which inturn is secured to an eye bolt I6, passing through a screw eye I! fixedber threads.

'4 in the rail I. The bolt has a wing nut I8 at its lower end, by meansof which the effective length of the bolt I6 may be varied, therebyvarying the tension of the spring I 5 and thus varying the retardingforce applied by the brake band to the brake drum.

At its upper part the bracket 9 is provided with parallel horizontalarms I9 having downwardly directed open slots 20 and 2I for thereception of the ends of shafts 22 and 23, respectively, carryingpresser rolls 24 and 25. The shafts are free to turn in the slots 20 and2I and also to rise and fall so that the rolls 24 and 25 may move bodilytoward and from the periphery of the tensioning roll I I. Preferably therolls 24 and 25 are of substantially less diameter than the tension rollII.

The bracket 9 preferably carries a yoke member 26 (Figs. 1 and 3) havinga series of spacer pins 21 directed toward the periphery of the tensionroll I I and defining a series of stalls for the reception of the ribbonrubber strands.

A divider device (Fig. 4), comprising a frame 28 having horizontalparallel rearwardly directed arms 29 and 30, is secured to the rear sideof the rail I at the lower part of the latter. This frame 28 supports apair of parallel, freely rotatable divider rolls 3I and 32. Preferably,the arm 29 has socket bearings for the reception of one end of each ofthe rolls 3I and 32, respectively, while the arm 30 has openingsextending all of the way through it and forming bearings for theopposite ends of the rolls 3I and 32. The rolls may be inserted bypushing them endwise through the openings in the arm 30, and the latteris provided with a cover plate 33, pivoted at 34 and which may be swungdown so as to be parallel to the arm 30 and thus to form a closure forthe bearing openings in the arm 30 after the rolls have been inserted.

Above this divider device there is preferably arranged a comb 35 (Fig.5) mounted on a fixed transverse bar or rail 36 of the loom structure.this comb having spaced parallel teeth 31 providing slots for thereception of individual rub- These slots are normally open at their rearends to facilitate insertion of the rubber threads, but may be closed bya closure plate 38 pivoted at 39 to one end of the comb device and whichin normal position overlies the ends of the teeth 3'! and thus closesthe spaces between them.

As illustrated, the tension device T is designed for handling ribbonrubber and for this purpose there is provided a receptacle 40 (Figs. 1and 2) i at the rear of the loom in which a supply of ribbon rubber maybe placed. Ribbon rubber 4|, as illustrated in Fig. 10, comprises aseries of rubber threads 42 arranged parallel to each other and in thesame plane, and with their adjacent edges cohering. However, while thethreads cohere to the extent that the assembly may be handled as a unitin the form of a ribbon or tape, the constituent threads which are veryuniform and all in substantially the same state of initial relaxation,are readily separated merely by pulling them apart. In accordance withthe present invention, the ribbon rubber 4I maybe piled into thereceptacle 40 without especial care and under no initial tension. Theribbon rubber is led from this supply 40 up and over guide rollers 43and 44, then down beneath a guide roller 45, forwardly beneath the railI, and beneath a guide roller 46, then up through one of the stallsdefined by the guide pins 21, and thence over the presser roll 24. It iscontemplated that several strands of ribbon rubber will be delivered atthe same time through the tension means, and when several ribbons arethus to be delivered simultaneously it is preferable to arrange themsymmetrically so that the same number of ribbons will lie at each sideof the center of length of the tension roll H and preferably at the samedistances from the center of the roll The separating pins 21 facilitatesuch arrangement.

The ribbon rubber passes over the roll 24, thence down between the roll24 and the tension roll N, then down and around the lower part of theroll N, then between the roll II and the presser roll 25, over the roll25 and then down to the dividing means, the latter being locatedsubstantially directly below the point of tangency of the ribbon rubberwhere it leaves the roll 25. At the dividing means the alternate threads42 forming the ribbon rubber are caused to pass about the guide roll 32and then upwardly to the comb 35, while the intervening constituentrubber threads pass about the roll 3| and thence upwardly to the comb35.

It may be noted that in the arrangement shown, the ribbon rubberapproaches the tensioning means T under substantially no tension, theonly tension imposed being that sufiicient to lift it out from theloosely piled mass in the receptacle, and lead it to the presser roll24. On the other hand, the guide rolls 3| and 32 of the dividing meansare so located that the tension force imposed on the rubber threads bythe weav ing operation tends to pull the presser roll 25 bodilydownwardly and toward the tension roll H, and the greater the tensionapplied to the rub-ber elastic threads between the presser roll 25 andthe fell of the cloth, the more the ribbon rubber is compressed by theroll 25 where the ribbon rubber passes between the tension roll II andthe presser roll 25. The compression to winch the ribbon rubber is thussubjected is substantially proportionate to the eifective tensioningforce which stretches the rubber elastic yarn as it approaches the fellof the cloth. As the tension increases the ribbon rubber is squeezedmore and more firmly against the surface of the roll II and eventuallythe frictional drag of the rubber against the roll II will turn thelatter in opposition to the action of the brake band l3, thus lettingoff suflicient length of the ribbon rubber to restore the tension to thenormal operating tension. Since the resistance imposed by the brake bandl3 may be adjusted as desired, it is thus possible to determine thetension at which the rubber threads will be delivered into the clothwith great nicety, it being noted that there is always a substantiallyuniform length of rubber thread undergoing tension so that the imposedload is always distributed throughout the same length of material.

By the employment of this tensioning device it becomes unnecessary towind the rubber elastic threads on a warp beam, whether or not ribbonrubber or initially independent rubber threads or covered rubber threadsbe employed, thus avoiding all of the difiiculties incident to thewinding and preparation of a beam of rubber warps; the provision of thecomplicated let-off mechanisms essential to the use of a beam of rubberwarps is avoided; and the space requisite for the installation of a warpbeam and the let-off mechanism is thus saved, since the tensiondevice ofthe present invention occupies but very little space and may beinstalled at a point in the loom structure which is normally free andavailable for the purpose.

While the tension device of the present invention is very useful, incombination, in a weaving loom structure, it is also useful in othertextile machines in which rubber elastic threads must be fed under adefinite tension. Thus, for example, it is highly useful in a braidingmachine, as illustrated for example in Figs. 6 and 7. In Fig. 6 thenumeral designates a conventiona1 braiding machine having carriers 5|each designed to support a yarn mass 52 from which the yarn 53 is led tothe braiding die, not shown. In the arrangement shown in Figs. 6 and '7,rubber elastic threads 42 are delivered to the braiding die so as toform a core within a tubular braid formed of the textile yarns 53. Forthis purpose there is provided a guide roll 54 carried by a suitablesupporting bracket 55 and so located as to deliver the yarns 42 directlyto the braiding die. These strands 42 may be the constituent threads ofribbon rubber 4| derived from a suitable source of supply such as a boxor other receptacle 40. The tensioning device T is substantiallyidentical with that above described in its essential characteristicscomprising a bracket 9 which supports the tension roll H and the presserrolls 24 and 25. However, in this instance, as illustrated in Fig. 7,the shaft of the tensioning roll I I is provided at each end with abrake drum or pulley |2 embraced by a brake band |3 provided with meansi 5, l6, l8, for varying its tension.

The tensioning mechansim T is mounted upon a suitable base or support 56and the base of the bracket 9 is preferably provided with a downwardlydirected lip or flange 51 (Fig. 6) which engages the vertical rearsurface of the support 56 and thus opposes tipping of the bracket 9 inresponse to the tension of the ribbon rubber 4| on its way to the guide54.

In this instance the bracket 9 is shown as provided with rearwardlydirected arms 58 which support a guide roller 59 beneath which the ribbon rubber passes on its way to the presser roll 24. The arms 58 alsosupport a vertical panel 60 having series of staggered openings 6|designed to receive spacer pins 62. With this arrangement the spacerpins may be plugged into the openings 6| at desired points to formguideways for various widths of ribbon rubber 4| and also to locateseveral strands of the ribbon rubber symmetrically with respect to thecenter of length of the roller While ordinarily a single strand ofribbon rubber is arranged to pass between the presser rolls and thetension roll II, at any given point, it is possible to obtain goodresults and at the same time to deliver a greater number of rubberelastic threads by superposing one or more ribbon rubber strands 4| asthey are delivered to the tensioning means. Such an arrangement isillustrated in Figs. 6 and 8, where three strands of ribbon rubber areshown in superposed relation said three strands being treated in thesame way as the ,single strand above described and being delivered as aunit to the tensioning means as many such units being used as necessaryto obtain the desired number of threads.

As illustrated in Fig. 6, the guide roll 54 is so located relatively tothe presser roll 25, that tension imposed upon the ribbon rubber betweenthe roll 25 and the braiding point, tends to pull the roll 25 downwardlytoward the tension roll H, thus pressing the ribbon rubber more and 7more firmly against the roll I I as the tension increases, and thusinsuring firm frictional engagement of the rubber with the roll H, suchas to cause the roll H to turn whenever the tension reaches a certainpredetermined amount.

In Fig. 9 a further utility of the tensioning means is illustratedwherein it is shown as employed for feeding rubber-elastic threads to abraiding machine for incorporation in the braided fabric. In Fig. 9 aconventional braiding machine BI is shown having movable carriers 62,each supporting a yarn mass 63 from which the yarn 64 .extends to thebraiding point. The machine also comprises guides 65 for therubberelastic threads 42. The tensioning means T is similar in allrespects, if desired, to that shown in Fig. 6, or that shown in Fig. 1,and is designed to receive ribbon rubber M which passes over the presserroll 24 under the tension roll II and over the presser roll 25, and thento dividing means comprising a guide roll 65 mounted in a bracket 66which also has bearings for the dividing rolls SI and 32. The ribbonrubber passes beneath the roll 65 and then alternate constituent rubberthreads pass beneath the roll 3| while the intervening threads passbeneath the roll 32, the separated rubber threads 42 then extending upto the several guides 65 and thence to the braiding point where they areinterbraided with the textile yarns 64.

The use of the tensioned rubber strands to supply the force forcompressing the rubber threads between the tensioning rolls, makesunnecessary the usual complexity of adjustable weights, levers, etc.,heretofore usually employed.

While as above noted the application of the present invention isespecially valuable in connection with the use of ribbon rubber, itfunctions equally well in dealing with ordinary individual iubberelastic threads or covered rubber threads, whether delivered fromspools, tubes, cones or even from a loose mass in a box or otherreceptacle. Desirably, although not necessarily, in handling individualthreads so supplied, a separator device or comb is employed to insureproper distribution of the threads leading to or to and from the tensionrolls. The lengths of the tensioning rolls may be varied according tothe number of threads to be handled, the number varying from one to onethousand or more, according to the type of apparatus being served bythis tensioning means. The device is far simpler than ordinarytensioning means; the winding of the rubber-elastic threads upon warpbeams is made unnecessary; and a far more uniform tension is obtainedthan in an previous construction employed for the purpose.

While certain desirable embodiments of the invention have beenillustrated by way of example, it is to be understood that the inventionis broadly inclusive of any and all modifications falling within theterms of the appended claims.

I claim:

1. Apparatus for delivering rubber elastic threads under tension to apoint of use comprising, a container for ribbon-rubber, means forseparating the ribbon-rubber into its constituent threads and forguiding said threads to a point of use, and tensioning means interposedbetween the container and the dividing means, said tensioning meanscomprising a rigid, smoothsurfaced, rotatable tension roll which ispartially embraced by the ribbon-rubber as the latter advances, brakemeans imposing a substantially constant retarding force opposingrotation of the tension roll, a first presser roll which is bodilymovable toward and from the periphery of the tensioning roll and whichis so constructed and arranged as to press the ribbon-rubber against theperiphery of the tensioning roll at its first point of .contact with thelatter, a second presser roll also bodily movable toward and from theperiphery of the tensioning roll and spaced from the first presser rollabout the periphery of the tensioning roll approximately theribbonrubber passing between the presser rolls and the tension roll andpartiall embracing each presser roll, the second presser roll beingarranged to contact the ribbon rubber at the point of tangency at whichthe latter leaves the surface of the tensioning roll, the parts being soconstructed and arranged that the ribbon-rubber urges the second presserroll toward the tensioning roll with a force proportionate to that whichadvances the ribbon-rubber.

2. Apparatus for delivering rubber elastic threads under tension to apoint of use comprising, a container for ribbon-rubber, means forseparating the ribbon-rubber into its constituent threads and forguiding said threads to the point of use, and tensioning meansinterposed between the container and the dividing means, said tensioningmeans comprising a rotatable tension roll which is partially embraced bythe ribbon-rubber, a brake band for retarding rotation of the tensionroll, one end of the brake band being attached to a tension spring andits opposite end being attached to the frame of the machine, a pair ofpresser rolls whose axes are parallel to that of the tension roll, andwhich are spaced apart from each other, each of said presser rolls beingbodily movable toward and from the tension roll, the ribbon-rubberpassing over one of said presser rolls between said latter presser rolland the tension roll, partially about the tension roll and then betweenthe latter and the second presser roll, and then to the dividing means,the parts being so designed and arranged that in passing about the firstpresser roll, the tension of the ribbon-rubber urges the first presserroll toward the peripheral surface of the tensioning roll, the secondpresser roll urging the ribbonrubber toward the tension roll with aforce which is proportionate to the force which advances theribbon-rubber.

FRANK TAYLOR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 49,271 Hull Aug. 8, 1865 70,253Painter Oct. 29, 1867 108,826 Randall Nov. 1, 1870 177,543 Nichols May16, 1876 951,888 Rhoades Mar. 15, 1910 985,543 Pepperell Feb. 28, 19111,024,528 Sibley Apr. 30, 1912 1,454,767 Porter May 8, 1923 1,781,817Kenyon Nov. 18, 1930 2,082,744 Shaw June 1, 1937 2,165,986 Shaw July 11,1939 2,169,886 Shaw Aug. 15, 1939 2,329,374 Holden Sept. 14, 19432,370,0 2 Dudley Feb. 20, 1945 2.373.091 Astley Apr. 10, 1945

